User-Defined Fit Functions

Create your own fitting functions using Igor Pro's built-in programming language.

Igor Pro's New Fit Function dialog helps you create fitting functions. You just type arithmetic expressions.

User-defined fit: Piece-wise linear fit

User-defined fitting functions can be arbitrarily complex, involving conditionals, loops, convolution, solutions of ODE's, etc.

Time-consuming fit functions can be implemented in C or C++ using the XOP Toolkit.